1. Field of the Invention
This invention relates generally to the field of visual display systems. In particular, this invention relates to a visual display system which employs a holographic film to generate a real image of a terrain surface.
2. Description of the Prior Art
A wide variety of visual display devices are available for the viewing of a terrain surface by a trainee pilot during simulated flight maneuvers. Such prior art devices include a programmed display apparatus which is a motion picture recording of a real world terrain surface along a fixed flight path. However, this device of the prior art ordinarily leaves something to be desired in that the trainee pilot is restricted to a fixed flight path and does not have the freedom to deviate from the fixed flight path.
A second device of the prior art utilizes a single large photograph for simulation of a terrain surface allowing for unprogrammed lateral excursions of the terrain surface. However, the perspective view of the terrain surface is fixed when the photograph is made. Therefore, for example, if a camera which made the photograph only saw the north side of a building, then the photograph will not contain any display of the south side of the building. This results in an unrealistic visual display of the building being presented to the trainee pilot during simulated flight maneuvers.
A third device of the prior art utilizes computer generated imagery consisting of an electronically stored terrain surface model which can be electronically manipulated and displayed from various perspective observation points. However, the present state of the art, as to computer generated imagery, limits the amount of detail in the terrain surface which can be displayed in real time. This limitation causes the terrain surface to appear unrealistic.